Absorber system

ABSTRACT

An absorber system solves problems of known absorber systems for use in solar fields in that the absorber tube is suspended on a rail below an absorber cover. The design also makes it possible to move measuring and cleaning robots and the like along the absorber tube more and allows the absorber tube and the secondary reflector to be jointly suspended, whereby an exact mutual alignment between the two components is enabled.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and Applicant claims priority under35 U.S.C. §§ 120 and 121 of continuation U.S. application Ser. No.17/088,988 filed Nov. 4, 2020, which claims priority on U.S. applicationSer. No. 15/128,504 filed on Sep. 23, 2016, now U.S. Pat. No. 10,941,963issued Mar. 9, 2021, which application is a national stage applicationunder 35 U.S.C. § 371 of PCT Application No. PCT/DE2015/100124 filed onMar. 24, 2015, which claims priority under 35 U.S.C. § 119 from GermanPatent Application Nos. 10 2014 104 030.9 filed on Mar. 24, 2014 and 102014 104 100.3 filed on Mar. 25, 2014, the disclosures of each of whichare hereby incorporated by reference. A certified copy of each ofpriority German Patent Application No. 10 2014 104 030.9 and of priorityGerman Patent Application No. 10 2014 104 100.3 is contained ingrandparent U.S. application Ser. No. 15/128,504. The InternationalApplication under PCT article 21(2) was not published in English.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an absorber system comprising anabsorber mounting, an absorber support apparatus, and an absorber cover,as well as an absorber tube that is suspended on a support carriage on arail element supported by the absorber support apparatus.

2. Description of the Related Art

Such an absorber system is already known from the German patent DE 102011 088 829 B3. There, it is proposed that an absorber tube issuspended on a rail using a carriage arrangement. This involves, in aconcrete embodiment, a double-T rail, into which roller elements engageon both sides, which elements carry a carriage that can move along therail. The absorber tube is suspended on this carriage and is positionedelevated above the primary reflectors distributed all around it, in sucha manner that these deflect the incident light onto the absorber tubeand heat it within the scope of line focusing.

In concrete terms, the solution proposed provides, first of all, for asupport structure that is formed, in simplified terms, from aperpendicular support and a transverse strut that completes it at thetop. Holding frames that are formed to be essentially rectangular aremounted on this T-shaped arrangement, which can certainly also be formedin Y shape, for example, in a concrete embodiment. Spring tabs areformed in one piece with these holding frames, which tabs connect theelements braced between the individual load-bearing supports with theload-bearing supports. On the basis of these spring tabs, which formsolid-body articulations with regard to the load-bearing supports,equalization can take place if length changes occur due to temperaturedifferences, so that movements of the material that accompany the lengthchanges do not lead to damage.

Thus, first of all, the aforementioned rail element should be mentionedas an element between the individual load-bearing supports, on whichelement the absorber tube is suspended using the support carriage thatis longitudinally displaceable on the rail element. This makes itpossible to mount the absorber tube, which is subject to extremetemperature variations, so as to be movable on the rail element, to agreat extent, in order to avoid compression or excess stretching.Independent of this, DE 10 2011 008 829 B3 provides for an absorbercover, in which a secondary reflector is suspended, so that the latter,in turn, can be moved, at least in restricted manner, not only relativeto the absorber tube but also relative to the load-bearing support, byway of the solid-body articulations. In this regard, the absorber coveras such is formed in box shape and is, in turn, firmly connected withthe load-bearing supports. It consists of multiple individual parts,which each form sections of the housing and are set up, in up to threeparts, around the absorber tube and the secondary reflector.

However, from different aspects, the previously known solution appearsto be complicated and therefore expensive, and to bring somedisadvantages with it. For example, it can be stated, first of all, thatthe absorber cover, as a welded construction, is complicated to produce,since the hood parts, which are bent at right angles, must be connectedwith the load-bearing supports independently of one another.Furthermore, the individual hood parts must be assembled in such amanner that a movement of the support carriage of the absorber tubethrough the hood parts is possible at the same time, since the railsuspension is disposed above the housing formed by the absorber cover.This in turn exposes the support carriage of the absorber tube toweather influences, so that increasing wear must be expected. Mountingof the secondary reflector also requires separate measures in the regionof the absorber cover and the holding frame of the load-bearingsupports. The clip that accommodates the absorber tube overlaps the tubedirectly, so that heat transfer from the absorber tube to the clip takesplace and thereby the clip in turn is greatly heated. This clearlyincreases the material demands on the clip that holds the absorber tube,for one thing, as well as on the support carriage directly connectedwith this clip. For another thing, it leads to greater heat emission,since the emitting surface is clearly increased in size as a result.This greater emission must be considered to be efficiency-reducing, asheat loss. Finally, it appears complicated to undertake measurement ofthe present known structure using measuring instruments, because aseparate rail arrangement would have to be used for this purpose, inorder to implement continuous measurement of the solar radiationentering into the absorber tube.

SUMMARY OF THE INVENTION

Proceeding from this set of problems and the problems known inconnection with the state of the art, the invention has set itself thetask of proposing an absorber system that eliminates the numerousproblems of the state of the art, and makes both production andoperation of an absorber and the further installations required for thispurpose simpler and more efficient.

This task is accomplished by different aspects of the invention,particularly an absorber mounting according to the characteristics ofone aspect of the invention, an absorber mounting according to thecharacteristics of another aspect of the invention, an absorber coveraccording to the characteristics of a further aspect of the invention,an absorber support apparatus according to the characteristics of anadditional aspect of the invention, an absorber system according to thecharacteristics of another aspect of the invention, as well as a methodfor construction of an absorber cover according to the characteristicsof a further aspect of the invention. Practical embodiments of themethod and of the apparatus parts and of the system as a whole can bederived from the discussion below.

According to the invention, an absorber system essentially consists ofthree components, an absorber support apparatus, an absorber covermounted on the latter, as well as an absorber mounting on which theabsorber tube is mounted in suspended manner. In this regard, theabsorber mounting also comprises, according to the invention, a supportcarriage that can be moved on a rail element. However, the invention, incontrast to the state of the art, provides, in this regard, that a clipfor overlapping the absorber tube is assigned to the support carriage,which clip holds the absorber tube in place, with the interposition of aplurality of support elements distributed over the inside circumferenceof the clip, which elements are thermally insulating and, if applicable,also electrically insulating. In other words, more or less point-shapedcontacting of the absorber tube, which is very hot during operation, iscarried out, and furthermore proceeds using thermally insulating supportelements. Because of the circumstance that insulation of the absorbertube takes place directly upon its first contacting, the heat loss onthe basis of heat emission, heat conduction, and convection due toheating of unnecessary other components is minimized. Heat loss isrestricted exclusively to the absorber tube itself, to the greatestpossible extent.

Because of the circumstance that the support elements do not or hardlypass on the heat of the absorber tube, the clip and therefore also therest of the support carriage remain insignificantly above ambienttemperature, so that furthermore, the material stress on these elementscan be kept as low as possible.

In fact, the use of such support elements brings with it the problemthat these must be produced from a material that brings suitable thermaland, if applicable, electrical insulation with it. A ceramic material isparticularly suited for this, which material in turn brings with it theproblem that it is sensitive to impact. If, therefore, the supportelements are produced from ceramic, according to the invention, then thesupport elements can be permanently damaged by impacts on the absorbertube, which can occur due to thermal length changes of the tube. Forthis reason, it is particularly provided that measures for cushioningsuch impacts relative to the support elements are provided. Onepossibility for cushioning consists in that the support elements areaccommodated by means of accommodations for attachment to the clip,wherein these accommodations are disposed on a spring crosspiece, ineach instance. The spring crosspieces can be worked out of the solidmaterial of the clip, in that a material slot that faces in thecircumference direction is introduced underneath the accommodation, intowhich slot the material of the spring crosspiece can move in the eventof an impact. Thus, although the support element itself will not be ableto cushion impacts elastically, its accommodation on the clip will beable to do so, as the end effect.

An alternative to this consists in that a ductile inlay is disposedbetween absorber tube and support element or, alternatively, alsobetween support element and clip, in other words an intermediate layerthat consists of resilient material. Such a ductile inlay can beproduced from copper or aluminum, for example. Because of the requiredsize, essentially corresponding to the contact surface of the supportelement with the absorber tube or with the accommodation on the clip,such a ductile inlay causes practically no additional emission losses.

In an advantageous embodiment, the support elements can be profiled inthe longitudinal direction of the absorber tube, so that in particular,they have at least one groove that runs in the radial direction of theabsorber tube. In this way, support crosspieces are formed on both sidesof the groove, wherein the free ends of these support crosspieces enterinto direct contact with the absorber tube. In particular, the groovecan be prepared in such a manner so as to accommodate a weld seam of theabsorber tube within itself, thereby causing additional fixation betweenclip and absorber tube to occur.

The clip in turn, as has already been mentioned, is suspended on asupport carriage, which has one or more rollers. These rollers areprepared for accommodation on a rail element, along which the supportcarriage can be moved using the rollers. The rollers in turn areattached to spring crosspieces of the support carriage, which carriageessentially consists of a support body, into which, in turn, materialslots are introduced above and/or below the attachment of the individualrollers. Thus, it is possible here, as well, that in the event of animpact of the absorber tube or an impact on the rail element, thisimpact can be cushioned by means of a movement of the spring crosspiecein the direction of the material slot. If the spring crosspiece isdisposed centered in the support body of the support carriage, it ispractical to provide a material slot on both sides of the suspension ofthe roller element.

First of all, the clip that carries the absorber tube is thereforesuspended on a support carriage, and will hang downward due to gravity,in this respect. For further more precise alignment, extension arms canbe assigned to the clip on both sides, which arms allow support on anabsorber cover that overlaps the absorber tube. For this purpose, rollerelements can be assigned to the extension arms, which elements make itpossible for them to be supported on the inside of an absorber cover,rolling on it, so that here, too, mobility of the carriage ismaintained. Because of this three-point support on the rail element aswell as at two points of the absorber cover, the absorber tube gets intoa precisely defined position, and mobility still exists only in thelongitudinal direction of the absorber tube, which mobility must beguaranteed because of the temperature expansion of the tube. This allowsvery precise guidance of the solar radiation directly onto the absorbertube, by means of alignment of the primary mirrors.

It is known that a secondary reflector is assigned to the absorber tubein the immediate vicinity, in order to throw solar radiation reflectedby the primary mirrors, which misses the absorber tube, back onto theabsorber tube from the other side, and thereby to increase efficiency.Here, too, it is necessary to create very precise alignment between thesecondary reflector and the absorber tube. Because of the significantlylesser distances between the secondary reflector and the absorber tube,here it is actually significantly more important to implement precisealignment. Therefore, it appears practical, in contrast to the state ofthe art, to suspend the secondary reflector specifically not independentof the absorber tube, but rather to implement the suspension jointlywith the absorber tube. For this reason, spring elements can beadditionally assigned to the extension arms, by way of which elementsthe secondary reflector is assigned to the extension arms. Thereflector, as a hood construction, overlaps the absorber tube as well asthe clip that encompasses it, and in this regard is laid onto theextension arms of the clip. Because of the resilient attachment, impactsrelative to the secondary reflector are also cushioned, so that here,too, damage can be prevented to the greatest possible extent. Because ofthe joint, longitudinally movable suspension of absorber tube andsecondary reflector, these two elements maintain their reciprocalposition precisely, and this leads to more precise alignment of theincident energy radiation onto the absorber tube.

Supplemental to the secondary reflector, the latter can in turn besurrounded by a protective hood, once again, which hood is thereforedisposed between the secondary reflector and an outer absorber cover.Such a protective hood can particularly be produced from sheet steel,above all from stainless sheet steel, so that the protective hood inturn can also bring about a certain reflection. In the event of damageto the glass reflector, this protective hood composed of sheet steelprotects the material of the absorber cover from being greatly heated bythe incident radiation from the primary mirrors, and from being damagedas a result, if applicable.

A connection between the protective hood and the secondary reflector canbe produced by means of gluing, for example.

According to the invention, an absorber system furthermore has anabsorber cover that protects the absorber tube and the secondaryreflector that surrounds it from damage and contamination, toward theoutside. In contrast to the state of the art, however, it is provided inthis regard, according to the invention, that the absorber cover coversnot only the absorber tube and the secondary reflector, but also thecomplete suspension, so that penetration of contaminants, for exampledue to weather influences, is prevented to a great extent. This is ofgreat importance, particularly for the optical surfaces of the absorbertube and of the secondary mirror, in order to minimize cleaning cycles.The material stress with regard to weather influences that areeliminated as a result also increases the durability and the efficiencyof the arrangement. For this purpose, the rail element can be a C-railthat is open toward the bottom, for example, because here, too,penetration of external influences is made more difficult once again. Inthis case, the support carriage is provided essentially as aconstruction having a planar support body, which has rollers on bothsides, which are then threaded into the C-rail. However, many other railshapes, such as, for example, a double-T rail, can also be used.

The absorber cover consists of an absorber hood that is held in shapeusing portal-shaped holding frames distributed over its longitudinalexpanse. The holding frames overlap the absorber hood in such a mannerthat the absorber hood is practically suspended from the inner contourof the holding frames. In particular, it is provided that the holdingframes have a round or polygonal inner contour, so that conversely, theouter contour of the absorber hood is also configured to be arch-shapedor polygonal. In particular, it speaks in favor of a polygonalconfiguration that this brings with it great rigidity and allows preciseproduction.

In a further development of the absorber cover, it is provided that aholding bracket is assigned to the holding frames in the region of theinner contour, which bracket preferably projects, in the region of theapex of the inner contour, into the region spanned by the holdingframes. In this regard, the holding bracket is open toward the bottomand is suitable for accommodating the rail, a C-rail or double-T-rail inthe example. This means that the holding bracket replicates the outercontour of the rail at least essentially, so that the rail can be pushedthrough the holding bracket, but merely possesses degrees of freedom inits longitudinal direction there. In this way, dropping out downward isprevented in spite of the configuration of the holding bracket, which isopen downward. In this regard, the opening width of the holding bracketcorresponds essentially to the opening width of the rail, so that thesupport carriage can be moved in the rail and can move past the holdingbracket without hindrance, because of the opening in it.

The absorber hood, which is produced as a one-piece element and can bebrought into the desired outer contour by means of bending, for example,has accommodations in the region of its apex, which allows the holdingbrackets to be passed through the material of the absorber hood. Thisbrings the absorber cover into precise contact with the holding frames,for one thing; on the other hand, this replicates the inner contourenclosed by the holding brackets on the inside of the absorber hood.After the absorber hood has been put together with the holding frames inthis manner, subsequently the rail can be pushed through the holdingbrackets that project into the interior of the absorber hood, below theabsorber hood, so that in this way, a first fixation between absorberhood and holding frames is created, using the rail. To complete theabsorber cover, the rail can be pressed against the holding bracketusing clamping elements, for one thing, in that a clamping element isused that spreads out between absorber hood and rail, using a clampingscrew, for example. At the free ends of the holding frames, the lattercan be connected with the absorber hood by means of face-side screwconnections, for example.

This overall construction composed of absorber cover and an absorbermounting that lies within it, as well as an absorber tube suspendedthereby is now disposed on an absorber support apparatus that is forkedon its side facing the absorber cover, and keeps a travel path clearbetween two fork struts, in each instance, for a travel carriage thatcan be moved below the absorber cover, in the longitudinal expansedirection. Because the absorber cover does not require a transversestrut between a fork of the load-bearing support or the free ends of theholding frames, respectively, because of the construction, sufficientspace is established in which a travel carriage can move below theabsorber tube, in the longitudinal direction of the latter. This spacecan be aligned, without interruptions, relative to the absorber tube,since an interruption, for example by means of transverse struts of theload-bearing supports, as is shown in the state of the art, does nottake place. In this regard, travel surfaces can be assigned to the forkstruts or also to the absorber cover, on both sides, on which surfaces atravel carriage can be guided in the longitudinal expanse direction ofthe absorber tube. For example, such travel surfaces can be situated inthe immediate vicinity of the lower edge of the absorber cover, so thata travel carriage can be set onto both travel surfaces, and it is alsomade impossible for such a travel carriage to become derailed, due tothe lateral delimitations.

At some advantage, the individual load-bearing supports are formed, inthis construction, from multiple Y-shaped layers, which, although theyare jointly disposed on the load-bearing support, are held so as to bemovable relative to one another. In this regard, mobility is once againimplemented by means of a solid-body articulation, in that the forkstruts of the Y-arrangement are configured to be resilient, in eachinstance. This once again allows absorption of different temperatureexpansions of the materials that are carried by the load-bearingsupports, and prevents compression and expansion in the material.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the invention will become apparent fromthe following detailed description considered in connection with theaccompanying drawings. It is to be understood, however, that thedrawings are designed as an illustration only and not as a definition ofthe limits of the invention.

In the drawings,

FIG. 1 shows an absorber cover in a perspective, explodedrepresentation, at a slant from above,

FIG. 2 shows an absorber cover in a face-side frontal representation inthe viewing direction of the longitudinal expanse of the absorber cover,

FIG. 3 shows a detail of the apex of the absorber cover according toFIG. 2 , in a face-side top view,

FIG. 4 shows a detail of the free edges of the absorber cover accordingto FIG. 2 , in a face-side top view,

FIG. 5 shows the absorber cover according to FIG. 2 in connection with aload-bearing support, in a face-side top view,

FIG. 6 shows a support carriage in a lateral top view,

FIG. 7 shows the absorber cover according to FIG. 2 with the supportcarriage laid in, and a clip with extension arms attached to it, in aface-side top view,

FIG. 8 shows the absorber cover according to FIG. 2 without a supportcarriage, only with the secondary reflector laid in, and the protectivehood, in a face-side top view, as well as

FIG. 9 shows a complete absorber system, comprising an absorber cover,an absorber mounting, an absorber tube, as well as a load-bearingsupport and a travel carriage, in a face-side top view.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows an absorber hood 2, which has been produced from sheetsteel by bending, in one piece. The absorber hood 2 has a polygonalouter contour 4, as well as two recesses 3 in an apex region. In theregion of its longitudinal edges, the absorber hood 2 furthermore has abend. In the sense of an exploded representation, a holding frame 5 isshown above the absorber hood 2, which frame possesses a polygonal innercontour 7. In this regard, the polygonal inner contour 7 is shaped insuch a manner that it corresponds with the polygonal outer contour 4 ofthe absorber hood 2. Furthermore, the holding frame 5 has a holdingbracket 6 in its apex region, which bracket is open toward the bottomand encloses a recess. The polygonal outer contour 4 of the absorberhood 2 can be brought into contact with the polygonal inner contour 7 ofthe holding frame 5 by means of lowering the holding frame 5 in such amanner that the parts of the holding bracket 6 pass through the recesses3. As a result, the holding bracket 6 and the shape section enclosed byit project into the absorber hood 2, so that subsequently, acounter-engagement means can be pushed through this shape section.Because of this, separation of absorber hood 2 and holding frame 5 issubsequently made impossible, so that this measure firmly connectsabsorber hood 2 and holding frame 5 with one another. Supplementally,the holding frame 5 has screw surfaces at its free ends, by way of whicha screw connection with the absorber hood 2 can be brought about in theregion of the bend of the hood along its longitudinal edges. By means ofthis assembly step, which, in the simplest case, merely comprisespushing in a counter-engagement means, for example a C-rail foraccommodation of a support carriage, an absorber cover 1 according tothe invention is produced.

FIG. 2 shows the absorber cover 1 in a face-side top view, now withfurther added elements. The polygonal inner contour 7 of the holdingframe 5 is clearly evident; the absorber hood 2 now lies directlyagainst it. After the absorber hood 2 is caused to make contact, aC-rail 8 is pushed into the holding bracket 6, as shown in the figure,and subsequently clamped in place with a clamping apparatus 9. A travelsurface 11 was disposed at the free ends of the holding frame 5 or ofthe bend of the absorber hood 2, at their longitudinal edges.

FIG. 3 , as a detail, shows the attachment of the C-rail 8 at the apexof the holding frame 5. In this regard, the C-rail 8 has an essentiallyrectangular cross-section, wherein narrowing occurs in the region of theopening of the C-rail 8. This narrowing ensures precise positioning ofthe C-rail 8 in the correspondingly shaped holding bracket 6, for onething; for another, the bracket ensures centering of a support carriage28 that is guided in the C-rail 8 and will be shown later. After theabsorber hood 2 and the holding frame 5 have been joined together, theC-rail 8 can at first be easily pushed into the holding bracket 6 in thelongitudinal direction of the absorber hood 2. Subsequently, a clampingapparatus 9 disposed above the C-rail 8 is clamped in place by means ofscrewing a clamping screw in relative to the C-rail 8. This takes placein that the fixed clamping apparatus 9 is pressed away from the C-rail 8by means of penetration of the clamping screw 10, which leads to theresult, as a reaction, that the C-rail 8 is pressed into the contour ofthe holding bracket 6, because of the impossibility of evasion of theclamping apparatus 9. In this way, a very simple but effectiveconnection between absorber hood 2, holding frame 5, and C-rail 8 comesabout.

FIG. 4 shows the free end of the holding frame 5, around which a bend inthe region of the longitudinal edge of the absorber hood 2 is passed. Anadditional profile element is set onto this bend by means of screwing iton; this element implements a travel surface 11 on the inside of theabsorber hood 2.

FIG. 5 shows a combination of the absorber cover 1 shown in FIG. 2 ,which is connected with a load-bearing support 13. In this regard, aconnection once again takes place by means of a screw connection 14 inthe region of the respective free ends of holding frame 5 andload-bearing support 13, so that a further space is encompassed betweenthe holding frame 5 and the load-bearing support 13. A travel path 16for a travel carriage is kept clear in the lower region of this space;the carriage can be set onto the travel surfaces 11 and hangs throughinto the travel path 16. Because of the lateral delimitations of thetravel surfaces 11 by the absorber hood 2 or the absorber cover 1,lateral slipping of a travel carriage 35 positioned in the travel path16 is prevented, as will be shown later. The lateral fork struts 15 areconfigured as a solid-body articulation in the case of the load-bearingsupports 13, in other words produced from a thin spring steel, so thatthey can give way in the longitudinal direction of the absorber tube.

FIG. 6 shows the support body 17 of a support carriage 28, which issupposed to be moved in the C-rail 8 of the absorber cover 1. Forintroduction into the C-rail 8, the support body 17 has an arrow-shaped,end-position threading aid 21 at both ends, in each instance, which aidfacilitates pushing the support carriage into the C-rail 8. Rollers 18,which are disposed on both sides, at the front and at the back of thesupport body 17, are directly accommodated in the C-rail. These rollersare attached to a spring crosspiece 19, in each instance, which, in theexample shown, is disposed centered in the support body 17. As a result,it is necessary to separate these spring crosspieces 19 from the supportbody 17 on both sides, using material slots 20, so that in the event ofa vertically directed impact, the spring crosspieces 19, together withthe rollers 18, can move into the material slots 20. As a result, it ismade possible to already absorb some impact force in the spring elementformed in this manner.

FIG. 7 shows the combination of a cover 1 as already described in FIG. 2and a support carriage 28 supplemented with a clip 22. The support body17 is threaded into the C-rail 8 with its rollers 18 and carries theclip 22, which is formed in circular shape with a clip gate 23. The clip22 can be laid around an absorber tube 37, which will be shown later, byopening the screw connections 24, and will then contact the tube allaround with support elements 25. This results in fixation of theabsorber tube 37 using the support elements 25, so that an encompassingthree-point suspension is created. In this regard, the support elements25 are produced from ceramic, so that it is necessary to dispose thesupport elements 25 on a spring crosspiece 26, in each instance, whichcrosspiece in turn is spaced apart from the actual clip 22 by a materialslot 27. Because of the fact that the material slot 27 is only delimitedspatially, however, the spring crosspiece 26 is still connected with theclip 22. Extension arms 29 are disposed laterally on the clip 22, onboth sides, which arms offer lateral support relative to the absorberhood 2, using the end-position roller elements 30. As a result, lateralback-and-forth movement of the arrangement is prevented. Furthermore,spring elements 31 are disposed on the extension arms 29; a secondaryreflector 33 and a related protective hood 34 can be set onto theseelements.

FIG. 8 shows these additional elements, which are not shown in FIG. 7for the sake of clarity. The combination of secondary reflector 33 andprotective hood 34 can be set onto the spring elements 31 using a springsupport 32, so that simultaneous displacement or expansion of absorbertube 37 and secondary reflector 33 is made possible. This allows veryprecise reciprocal alignment, so that great efficiency can be achievedin passing on the energy from the secondary reflector 33 to the absorbertube 37. In the event of damage to the secondary reflector 33, thearrangement of the secondary reflector 33 around the protective hood 34,which is connected with the reflector by means of gluing, for example,protects the absorber cover 1 from damage caused by the concentratedincident sunlight.

FIG. 9 shows a complete absorber system, comprising a load-bearingsupport 13, onto which an absorber cover 1 is laid. The absorber cover 1comprises an absorber hood 2, which is laid over an absorber tube 37 andprotects the latter from weather influences. A support carriage 28 thatholds the absorber tube 37 in position is also accommodated under theabsorber hood 2. Because of this construction, a travel path for atravel carriage 35 is kept clear below the absorber tube 37, betweenlateral fork struts 15 of the load-bearing support 13; the carriage canbe set onto a travel surface 11 in the edge region of the absorber cover1, using roller elements 36. Such a travel carriage 35, for example witha measuring robot for measuring the radiation of the individual primarymirrors that impacts the absorber tube 37, is thereby able to carry outmeasurements along the entire absorber tube 37, without having to beremoved in between or without being interrupted by transverse struts.

Thereby, an absorber system comprising an absorber cover, an absorbersupport structure, as well as an absorber mounting has been describedabove, wherein the mounting mounts an absorber tube in longitudinallymovable manner. Because of a novel construction of the absorber cover,the latter allows weather-protected mounting of the support carriage onwhich the absorber tube is suspended, for one thing, in other words asimple and cost-advantageous construction. Because of its thermal andelectrical insulation solution, the absorber mounting offers moreefficient suspension of the absorber tube, for another thing, andreduces energy losses due to heat emission. The construction of theabsorber support structure furthermore allows an intelligent arrangementof travel carriages that can be moved in the region of the absorbertube.

Although only a few embodiments of the present invention have been shownand described, it is to be understood that many changes andmodifications may be made thereunto without departing from the spiritand scope of the invention.

REFERENCE SYMBOL LIST

-   -   1 absorber cover    -   2 absorber hood    -   3 recess    -   4 polygonal outer contour    -   5 holding frame    -   6 holding bracket    -   7 polygonal inner contour    -   8 C-rail    -   9 clamping apparatus    -   10 clamping screw    -   11 travel surface    -   12 screw connection    -   13 load-bearing support    -   14 screw connection    -   15 forked strut    -   16 travel path    -   17 support body    -   18 roller    -   19 spring crosspiece    -   20 material slot    -   21 threading aid    -   22 clip    -   23 clip gate    -   24 screw connection    -   25 toothed element    -   26 spring crosspiece    -   27 material slot    -   28 support carriage    -   29 extension arm    -   30 roller element    -   31 spring element    -   32 spring support    -   33 secondary reflector    -   34 protective hood    -   35 travel carriage    -   36 roller element    -   37 absorber tube

What is claimed is:
 1. An absorber mounting comprising a supportcarriage configured for suspended mounting of an absorber tube on a railelement; wherein the support carriage is movable along the rail element;wherein the support carriage is disposed beneath an absorber cover;wherein a clip configured to encompass the absorber tube, is mounted tothe support carriage, wherein the clip has first and second sides andextension arms on the first and second sides and is supported on theabsorber cover that is disposed in part around the absorber tube, andwherein spring elements are assigned to the extension arms, wherein asecondary reflector that is disposed above the absorber tube and belowthe absorber cover is attached on the spring elements.
 2. The absorbermounting according to claim 1, wherein in addition to the secondaryreflector, a protective hood is disposed between the secondary reflectorand the absorber cover, wherein the hood is also attached to the springelements of the extension arms, directly or indirectly.
 3. The absorbermounting according to claim 2, wherein the protective hood is producedfrom sheet steel.